{"id":"F2008L02889","name":"AD/PHZL/91 - Hub Blade Socket Lubrication Holes","slug":"ad-phzl-91-hub-blade-socket-lubrication-holes","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":74782,"registerId":"commonwealth-F2008L02889-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Propellers - Variable Pitch - Hartzell","sectionType":"division","heading":"Propellers - Variable Pitch - Hartzell","content":"### Propellers - Variable Pitch - Hartzell\n\n| AD/PHZL/91 | Hub Blade Socket Lubrication Holes | 9/2008 |\n| ---------- | ---------------------------------- | ------ |\n\n| Applicability: | Hartzell Propeller Inc. left-hand rotating ( )HC-( )(2,3)Y(K,R)-2 two- and three-bladed, aluminium hub, “compact” series propellers, with hubs having a non-suffix serial number (SN), and lubrication holes located on the shoulder of the hub blade socket installed on Lycoming Engines LIO-360 series and LO-360 series reciprocating engines, installed on Piper Aircraft, Inc. Seneca PA-34-200 and Seminole PA-44-180, and Hawker Beechcraft Corporation Model 76 Duchess, aeroplanes.Note 1: The parentheses appearing in the propeller model number indicates the presence or absence of an additional letter(s) that varies the basic propeller model. This AD still applies regardless of whether these letters are present or absent in the propeller model designation.                                                                                                                                                                                                                                                                                                                                                           |\n| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. Perform an Eddy Current Inspection (ECI) of the area around the lubrication holes of the hub blade sockets in accordance with paragraphs 3.A. through 3.A.(3)(d) of Hartzell Propeller Inc. Alert Service Bulletin (ASB) No.HC-ASB-61-297, Revision 1, dated 14 November 2007.2. If any cracks are found, remove the propeller hub from service.3. If no cracks are found, mark the propeller using paragraph 3.A.(5)(a) of the Accomplishment Instructions of Hartzell Propeller Inc., ASB No.HC-ASB-61-297, Revision 1, to indicate compliance with this ASB.4. Do not install on any engine in any aircraft propeller hubs that have a non-suffix SN, or an ''E'' suffix letter in the SN removed from affected propellers in this AD.Optional Terminating ActionAs optional terminating action to the repetitive ECIs required by this AD, replace the non-suffix SN propeller hub with a propeller hub identified by an ''A'' or ''B'' suffix letter in the propeller hub SN.Replacement propeller hub part numbers can be found in paragraph 2.A., Material Information, of Hartzell Propeller Inc. ASB No. HC-SB-61-297, Revision 1. |\n\n|             | Previous CreditECIs of the propeller hubs done before the effective date of this AD that use Hartzell Propeller Inc. ASB No. HC-SB-61-297, dated 17 September 2007, comply with the requirements specified in this AD.Later revisions of the above SB, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2008-13-28 are considered acceptable for compliance with the equivalent Requirements of this Directive.Note 2: FAA AD 2008-13-28 Amdt 39-15591 dated 19 June 2008 refers. |\n| ----------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Compliance: | For Requirement 1:Initial inspection within 50 flight hours after the effective date or within 12 months after the effective date of this AD, whichever occurs first, unless previously accomplished; andThereafter repetitively at intervals not to exceed 50 flight hours or 12 months, whichever occurs first.For Requirement 2:Before further flight.For Requirement 3:At completion of the inspection as detailed in Requirement 1 of this AD.For Requirement 4:From the effective date of this AD.                                                   |\n|             | This Airworthiness Directive becomes effective on 28 August 2008.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |\n| Background: | The FAA has received four reports of propeller hub cracks, including two in-flight blade separation events. The issuing of this AD is intended to prevent failure of the propeller hub, which could result in blade separation and loss of control of the aeroplane.                                                                                                                                                                                                                                                                                       |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n16 July 2008","sortOrder":0},{"sectionNumber":"AD/PHZL/91","sectionType":"part","heading":"AD/PHZL/91","content":"## AD/PHZL/91","sortOrder":1},{"sectionNumber":"Hub Blade Socket Lubrication Holes","sectionType":"part","heading":"Hub Blade Socket Lubrication Holes","content":"## Hub Blade Socket Lubrication Holes","sortOrder":2},{"sectionNumber":"9/2008","sectionType":"part","heading":"9/2008","content":"## 9/2008","sortOrder":3}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":false,"description":"This directive adopts the FAA's corrective action (FAA AD 2008-13-28 is cited) and implements Hartzell ASB procedures; it does not broaden the applicability beyond the serial‑numbered compact-series hubs described (Applicability) and explicitly allows credit for earlier ECI work done per the manufacturer SB (Previous Credit; Note 2). The AD adds an installation prohibition for non‑suffix and 'E' suffix hubs and an optional terminating replacement path (Requirement 4; Optional Terminating Action), but these measures align with the corrective scope referenced rather than expanding it."},"complexity_factors":["Technical inspection method required is an Eddy Current Inspection (ECI) with specific ASB procedures referenced (Requirement 1; Hartzell ASB HC-ASB-61-297, Revision 1).","Recurring compliance schedule: initial within 50 flight hours or 12 months, then repetitively at intervals not to exceed 50 flight hours or 12 months (Compliance for Requirement 1).","Immediate operational constraint if defects found: remove propeller hub from service before further flight (Requirement 2; Compliance for Requirement 2).","Record/marking obligation after each inspection (Requirement 3).","Installation prohibition on certain hubs (non‑suffix SN or 'E' suffix) removed from affected propellers (Requirement 4).","Optional terminating action (replace hub with 'A' or 'B' suffix) removes need for repetitive ECIs but involves replacement cost and parts sourcing (Optional Terminating Action; Material Information paragraph referenced).","Cross‑references to manufacturer service bulletin and FAA AD introduce alternative methods/AMOCs and multiple acceptable revisions to track (Previous Credit; Note 2; FAA AD 2008-13-28).","Applicability is serial-number and model specific (compact-series HC-( )(2,3)Y(K,R)-2 two- and three-bladed hubs on listed engines/airframes), increasing administrative filtering for operators and maintainers (Applicability).","Prior‑compliance credit clause complicates record assessment for previously accomplished ECIs (Previous Credit).","Safety consequence motivating the AD is high (reported hub cracks and in‑flight blade separations), which raises urgency for timely compliance (Background)."],"plain_english_summary":"This directive requires operators of certain Hartzell compact-series aluminium variable-pitch propeller hubs fitted to specified Piper and Beechcraft aeroplanes to perform eddy‑current inspections of the lubrication‑hole area, remove any hub found cracked, mark hubs that pass inspection, and prohibit installation of hubs with non‑suffix or 'E' suffix serial numbers. Owners/operators must pay for inspections and any hub replacements and comply at the prescribed recurring intervals or adopt the optional terminating action (hub replacement with an 'A' or 'B' suffix)."},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope targeting specific Hartzell propeller models with identified safety defects. The optional terminating action (hub replacement) and previous credit provisions are standard aviation safety regulatory mechanisms that do not expand the scope beyond the original safety purpose of preventing hub failures."},"complexity_factors":["Highly specific technical applicability criteria involving nested model numbers with wildcard characters (parentheses indicating optional letters)","Multiple compliance pathways (initial inspection, repetitive inspection, optional terminating action via replacement)","Cross-references to external technical documents (Hartzell Alert Service Bulletin HC-ASB-61-297 Revision 1) without reproducing those instructions in the AD itself","Conditional logic: different actions required depending on inspection results (cracks found vs. no cracks found)","Serial number suffix parsing required to determine applicability (distinguishing non-suffix, \"E\" suffix, \"A\" suffix, and \"B\" suffix)","Reference to foreign regulatory equivalence (FAA AD 2008-13-28) and AMOC (Alternate Method of Compliance) provisions"],"plain_english_summary":"This AD mandates repetitive eddy‑current inspections of certain Hartzell “compact” aluminium propeller hubs (specific serial‑number patterns) on Piper Seneca PA‑34‑200, Piper Seminole PA‑44‑180 and Beechcraft Model 76 Duchess aircraft with Lycoming LIO‑360/LO‑360 engines. Cracked hubs must be removed from service; inspected hubs must be marked. Prompted by FAA reports — including in‑flight blade separations — inspections are required within 50 flight hours or 12 months and every 50 hours/12 months thereafter, or hubs may be replaced with newer‑suffix models."}},"importantCases":[],"_links":{"self":"/api/acts/ad-phzl-91-hub-blade-socket-lubrication-holes","history":"/api/acts/ad-phzl-91-hub-blade-socket-lubrication-holes/history","analysis":"/api/acts/ad-phzl-91-hub-blade-socket-lubrication-holes/analysis","conflicts":"/api/acts/ad-phzl-91-hub-blade-socket-lubrication-holes/conflicts","importantCases":"/api/acts/ad-phzl-91-hub-blade-socket-lubrication-holes/important-cases","documents":"/api/acts/ad-phzl-91-hub-blade-socket-lubrication-holes/documents"}}